Generally described, large turbine driven generators used in the production of electrical power and the like may include a rotor and a stator. The rotor serves as a source of magnetic lines of flux produced by a coil wound thereon. The rotor rotates within the stator. The stator may include a number of conductors in which an alternating current may be induced therein. Specifically, this rotation generates a magnetic field in a narrow gas gap between the rotor and the stator.
The overall power output of a generator may be limited by the inability to provide additional current due to a buildup of heat in the stator components and/or the rotor components. This generated heat should be dissipated to a cooling gas or other medium so as to avoid insulation failure and the like. Moreover, the lack of adequate cooling may result in a rotor winding hot spot. For example, a typical rotor winding hot spot may be found about the center line of the rotor. Specifically, many rotor designs may have a non-actively cooled centering pin positioned along the centering line. Reducing hot spot temperatures about the centering pin and elsewhere thus may increase the utilization of the rotor windings and the overall power output of the generator.